Internal-combustion engine



March 11 1924.

R. S. WITTMEIER INTERNAL"COMBUSTION ENGINE 4 Sheehs-Sheef 1 Filed Aug. 23, 1921 Rollef amztmeieii March 11 1924.

%\\ M m m r 4. 2 \R u w a H M Q %Q\ M n u 5 m m 0 S Q, g m flu. Mu 1 7 F g 4 fl R m m E 9 I N m m H T I m A m 6 R m T F I \Q Ml m (a NMQN m\\ .1 [IL I k n R. S. WITTMEIER INTERNAL COMBUSTION ENGINE 4 Sheef.sShet Filed Aug. 23, 1921 March 1 1 1924.

M rch 11 1924. 1,486,714

- R. S. WITTMEIER INTERNAL COMBUSTION ENGINE Filed Aug. "23, 1921 4 Sheer -Shpm. 4.

Patented er ll, i924.

ROBERT S. WITTMEIER, F PORTLAND, UBEGOIL INTERNAL-COMBUSTION ENGINE.

Application filed August 28, 1921.

T 0 all whom it may concern:

Be it known that I, ROBERT SRVITTMEIER, a citizen of the United States, residing at Portland, in the county of Multnomah and State of Oregon, have invented certain new plosion cylinden ill The general object of the present invention. is to provide an engine of the pro-com pression type simple in construction, eiiicient in operation, devoid of complicated operating parts, and capable, of being adjusted to meet the conditions under which it is used.

One feature of the present inventiortresides in the construction and arrangement of the means provided for compressing the charge before delivery to the explosion cylindcr, this means comprising charge compression cylinders which are cast integral with the heads of the explosion cylinder, the

valves which control the supply of fuel to the explosion cylinder from the charge compression cylinders and the exhaust of the fired charge from the explosion cylinder being likewise housed within the heads of the said explosion cylinder, to thus simplify the construction and render it more compact and lighter in weight. i

In engines of this type it has heretofore been customary to compress the charge through the reciprocation of pistons driven by a positive mechanical connection with the crank shaft of the engine and it has been impracticable to regulate or vary the degree of compression of the charge or the volume compressed with the result that an engine so constructed and designed for heavy duty work, will, if employed in performing lighter Work, be very vast-eful of fuel and diilicult of control. It is therefore another important object 01' the present invention to provide for actuation of the charge compression pistons in such a manner that these pistons may be adapted to compress a charge to a degree suitable for heavy duty work or to a lesser degree for light duty work,

Another object of the invention is to provide for the independent actuation of the charge compression pistons so that their 0p- Scrial No. 494,479.

oration may be more accurately timed and repairs more readily and economically effected; also, by providing for the-independent operation of these pistons, should the operating means for either piston fail to function because of a temporary disarrangement of the parts, the engine will still be capable of operating to a satisfactory degree until the, trouble can be located. and preparations made for repairs.

A further object of the invention is to provide a novel arrangement and. construc tion of inlet and exhaust valves as a result of which the admission of the charge and the exhaust of the products of combustion may be more accurately timed and controlled, and the explosion cylinder more thoroughly scavenged. Incidentally the invention contemplates regulation of the valves so as to suitably control the volume of fuel admitted to the explosion cylinder in accordance with the particular Work to be done and thus effect an economy in fuel.

Another important object of the invention is to provide means whereby the explosion cylinder and its piston may be utilized as a brake.

A further object of the invention is to provide for lubrication of the piston of the explosion cylinder by a circulation of "oil through the piston rod and within and about the piston head in a manner to also effect a cooling of these parts which has been found essential in engines of this type.

Other objects and advantages of the structure will be made clear in the specific description which is to follow.

In the accompanying drawings:v

Figure 1 is a top plan view of an engine constructed in accordance with the present invention v Figure 2 is a side elevation of the engine, one of the charge compression cylinders and some of its associated parts being shown in vertical section;

Figure 3 is a horizontal sectional view in detail taken substantially on the line 3-3 of Figure 2;

Figure at is a view partly in plan and partly in horizontal section illustrating the piston of the explosion cylinder;

Figure 5 is an end elevation of onebf the cylinder heads;

Figureli is a vertical sectional view on the line 6-6 of Figure 5 lookingin the threetion indicated by the arrows:

Figure 7 is a side elevation of one of the exhaust valve cams;

Figure 8 is a rear elevation of the cam;

Figure 9 is a side elevation of one of the inlet valve cams;

Figure 10 is a rear elevation thereof;

Figure 11 is a erspective view illustrating one of the sli e valves and the parts associated therewith;

Figure 12 is a group perspective view.

illustrating the parts comprising one of the tappets for actuating the charge compression pistons. p In the drawings the principles of the invention are illustrated as embodied in a stationary engine but it will be understood that the invention is in no way limited to this particular embodiment and that the structure may be modified in any manner found necessary in constructio the engine :g'or installation in an automo bile or in fact for use under any other conditions where an internal combustion engine may be employed. I

The explosion cylinder of the engine is indicated in general by the numeral 1 and may be supported in any manner found suitable depending upon the conditions under which the engine is employed, and this cylinder comprises a cylindrical body 2 open at both of its ends and having fitted and removably-securcd to its ends heads 3 and 4. Preferably the cylinder 2 is provided with a removable bushing" or lining wall 5 which is confined at its ends between the heads 3 and 4 when the heads are bolted in place but which may he removed for repair or replacement by removing either one or both of said heads. As the valves of the engine are contained within the heads 3 and 4, the bushing 5 is in the form of a cylindrical body imperforate throughout and may therefore bcmost economically produced. The piston which operates within the cylinder 1 is indicated in general by the numeral (5 and the same has connected to it a piston rod 7 which opcrates through the head 4 and which is connected as at 8 with a cross head 9 supported for sliding movcment upon a suitable base.

10. A pit'man 11 is opcrativcly connected with the c oss head 9 and with a crank 12 forming a part of a crank shaft 13 mounted in suitable bearings 14 and 15. In order to accommodate the-piston rod 7, the head 4 of the cylinder -is provided with an opening 16 and with a collar extension 17 that surrounds the opening and which has its bore 18 gradually flared or increased in diameter in the direction ofits outer end. Tapered or conical packingfgaskets 19 are arranged within the bore of the .collar extension 17 --and are forced into place to form a fluid tight paclringabor't the piston rod 7, by means of a packing nut 20 which is exteriorly threaded onto the said collar extension. The construction of the iston head 6 and its rod 7 to provide for In rication and cooling of these parts will presently be more specifically described. T e cylinder 2 is provided with a water jacket or outer wall 1 forming a water space 22 extending substantially continuously about its circumference, and the heads 3 and 4 of the said cylinder are provided respectively with water spaces 23 and 24 placed in communication with the cylinder Water space by way of ports 25 and 26 respectively, means being thus provided for cooling the cylinder walls and heads.

, The cylinder heads 3 and 4 are provided with intake ports 27 and 28 respectively and with exhaust ports 29 and 30 respectively, these ports being in communication with the respective ends of the explosion cylinder 1 as clearl shown in Figure 3 of the drawings. he numerals 31 and 32 indicate charge compression cylinders which are respectively cast integral with the heads, 3 and land placed in communication with the explosion cylinder 1 respectively by way of-the ports 27 and 28.

The exhaust manifold of the engine is indicated in general by the numeral 33 and the same is provided with branches 34 and 35 r espcctively placed in communication with the exhaust ports 29 and 30. The exhaust ports 29 and 30 are respectively controlled by slide valves 36 and 37 mounted for recipmention in the heads 3 and 4 respectively and each provided with a transverse rela tively narrow port 38 adapted to be brought into and out of communication with the respective ports 29 and 30 in the reciprocation of the valves. One of these valves as for example the valve 36 is clearly illustrated in Figure 11' of the drawingsand each of the valves is provided at its lower end with a. stem 39 which PI'OJOCtS downwardly and has pin and slot connection as at 40 with a rock arm 41 fixed upon one end of a short shaft 42 mounted beneath the respective head 3 or 4 as the case may be. A crank arm 43 is carried by the other end of shaft 42, and con net-ling rods 44 are pivotally connected to the upper ends of the arms 43 and are led rcarwardly and connected to the upper ends of similar crank arms 45-mountcd iupon short shafts 46 located one side of the support ll) for the cross head 9. Other rock arms 47 upstand from the shafts 46, and rods 48 are connected thereto and work through suitable guides 49. The rear ends of the rods 48 carry rollers 50 which are held in contact with th peripheries of cams 51 fixed upon the crank shaft 13, the rods being held with their rollers in engagement with the cams through the medium of springs 52 which are fitted onto the rods and Y bear between the guides 49 and collars 53 which are used upon the said rods. One

of the cams is illustrated in Figure 7 of-thc drawings and each is preferably formed in two sections one indicated by the numeral 5% and the other by the numeral 55, these sections being provided with bosses or ears 56 whereby they may be bolted together about the crank shaft 13 and being also provided, if desired, with threaded openings 57 so that set screws may be fitted through the sections 54 and 55 to biml against. the shaft and thus hold the cc-mssecurely in positions of adjustment. One section as for example the section 54 of each cam provided with a cam nose 58 having relatively abrupt ends 59 the advancing one of which is adapted to ride against the respective roller 50 and impart a sudden shifting motion to the re ective rod 48, and through th y medium of t e intermediate connections above tiescribed, to immediately move the corresponding exhaust valve 36 to open position, the valve being maintained in this position so long as the nose of the respective can: is riding against the respective. roller 56. Of course as soon as the opposite or follovv ing encl of the com ricles beneath the respective roller, the spring will return the respective rod i8 it iormel osition sud, through-the intermetiioe connections described, immeclistely move respective exhaust valve 36 to closed p0:

The supply of fuel through the intake ports 27 and 28 is controlled by istaite slide valves indicated respectively by the numerals 60 and 61 each of which is provided with a transverse relatively narrow intake passage or port 62. The valves $0 and 61 are furthermore of the same general construction as the valves 36 end 37' so that a specific rle scription thereof is Seemed unnecessary. The lower cuds of the stems of the valves 60 and 6t are connected b v pin and slot'conneqtion 63 to rock arms es which are fixed upon shafts 65 suitably supported beside the cylinder of the engine. Crank arms 66 upstand from the shafts 65, and rods 67 are connected as at 68 to these arms and extend rearv'verdly and are provided with pivot bolts 69 at their opposite ends which are adjustably engagecl'through'slots 70 formed in rocking links 71-vvhich project upwa-rdl from shafts 72 mounted parallel to the cram shaft of the engine. Crank arms 73 also upstand from the shafts '72,:1ml rods 741cm pivotally connected as at 75 with thessid arms73 and are provided at their ends with rollers 76 which are yicldably held in 0011- tact with the peripheries of cams 77 fixed upon the crank shaft 18, springs 78 being fitted onto the rods 74 and bearing between collars 79 which are fired upon the said rods,

and suitable guides 80 which support the rods for reciprocation. Une of the cams 7 7 is clezirlyjillustrated in Figures 9 and 10 of the dra win'gsand is of the some generslcon struction as the cams 51 except that the nose of the cam 77', which is indicated by the numeral 8i, merges at its Working edge at one end with the peripheral surface of the can] as at 82 and is gradually increased in height from this point to its opposite end which is indicated by the numeral 88 and which is of abrupt formation as shown in Figure 9. It will now be evident that as the noses 8170f the cams T7 ride against the respective rollers 76, the TBSP'SCl'lVG rods'i l will be shifted in a manner to e ct opening of the respective intake valves o l on immediate. closing of the valves as the rollers ride over the abrupt ends 83 of the said noses and the Charge compression pistons i l. and 85 re ciprocnte respectively in the charge compression cylinders 31 and erul each of these pistons comprises a. head 86 having; a rod 8? extending axially from its under side sud fitting through :i shilling box in the closcii lower end 89 of the lPSPLJllVG cvliir ticr. A cylindrical plate so is filled onto the lower end of ouch piston rod 8? and adapted to be ucljusml longz itu-zliuullv of the rod through the adjustment of a nut 91 threaded onto tho said end of the rod, this mt lacing preferably in turn hold in adjustment by means of o. juiub not 92 A co:u pression spring 33 is disposed about the rod 8? of each charge compression piston and bears at its lower and upon the respective plate and at its upper end against the closed lower end 89 of the respective charge compression cylinder and at this point it will be understood that when the piston of either cylinder is moved upwardly and then relcascrl, the respective spring 93 will first be COIEIHOSSHl and. will then lvc permitted to expand, in the latter instance forcing the piston on its downward stroke.

The upward movement of ihc charge comircssiou pistons s rves to draw into the re-' spcclive cylinders um charge to be compressed and dclivcrcillo tlic explosion cylinder L and with this cud in view an intake manifold E l cast upon one side of the cylinder 1 and is placed in communication at its ends with intake ports 95 and S16 provided respectively in the sides of the charge compression cylinders 31 and. 32 ut the lower ends thereof. Check valves of any suitable construction indicated by the numerals 97 and 98 are arranged in the opposite ends of the intake manifold 94 and permit the delivery of the charge from the manifold to the cylinders 31 and respcclively and prevent return of the charge to the said intake manifold, the check valves being preferably of the spring closed type and also being preferably removebly fitted into place so that they may be repaired if occasion arises. The intake manifold 94 is provided between its ends with on intake 99 which in practice will laced in communication with any suitaole carburet ngdevice.

faces 103 and with a squared or siouldered' lower end 104 whereby the tappet arms which will now be described may coact therewith. The tappet arms are indicated in general one by the numeral 105 and the other by the numeral 106 and are respectively associated with the stemsof the pistons S4 and 85. Each of these tappet arms comprises a collar 107 fixed in any suitable manner upon a respective one of a pair of rock shafts 108 mounted above the explosion cylinder, and each collar 107 is provided with spaced apertured ears 109 for the passage of a pivot pin 110 which fits also through interfitting pivot ears 111 formed at the inner ends of a pair of members 112 comprising the respective arm 105 or 106 as the case may be. A bolt 113 is fitted through aligned openings 114 formed in the members 112 of each arm and has fitted upon it a spring 115 which bears against the outer side of one of the members 112 and serves to yieldably urge the members toward each other. the members being capable however of pivotal movement against the tension of the spring 115 in a direction to effect their relative separation. Forwardly beyond the connecting bolt 113, the opposing sides of the members 112 are beveled as indicated by the numeral 116. It will now be understood that when the shafts 108 are rocked in one direction, the respective arms 105 or 100 as the case may be will be swung downwardly until the beveled surfaces .116 of their members 112 ride against the beveled surfaces 103 of the respective tappct head 102 whereupon, in further downwaid swinging movement of the said arm. the members 112 will be relatively separated against the tension of the spring 115 until their beveled portions ride past the lower end of the said tappet head 102 whereupon the spring 115 will act immediately to swing the members 112 toward each other so that their upper edges will engage beneath the lower end 104 of the tappet head 102 at the opposite sides of the stem 100. The said upper edges of the members 112 are curved or rounded in the direction of the free outer ends of the members as indicated by the numeral 117 so that these edges will 'act as cams. when the respective shaft 108 is rocked in a reverse diing transversely beneath the rods 120.

rection thereby exerting an upward pressure against the respective tappet head 102 and imparting an upward stroke to the respective charge compression piston 8 1. When the tappet arms reach a predetermined limit of their upward movement, they sweep from engagement with the respective tappet heads 102 thus releasing the respective charge compression pistons for their downward stroke under the influence of the respective springs 93.

In order that rocking motion may be imparted to the shafts 108 in timed relation to the functioning of the other operating parts of the engine. crank arms 118 are fixed upon the said shafts 108 and are pro vided with wrist pins 119. Connecting rods 120 are provided with open sided bearings 121 engageable over and resting by gravity in operative connection with the wrist pins 119 and capable therefore of be ing swung upwardly to become disengaged from the said pins. At their opposite ends the said rods 120 are connected to cranks or eccentrics 122 upon the shaft 13. It will now be evident that so long as the bearings 121 of the connecting rods 120 are in operative engagement with the wrist pins 119 and the crank shaft 13 is rotating, the charge compression pistons 81 and 85 will be operated but in order that this operation may be discontinued so as to render the said pistons 84 and 85 inactive and thus adapt the piston 6 to serve as a brake through compression of air in the opposite ends of the explosion cylinder 1, means is provided for swinging both of the rods 120 in an upward direction to inactive position and free from connection with the wrist pins 110. This means may vary in its struc tural details in accordance with the varying conditions under which the engine will as comprising a rock shaft 123 mounted upon any suitable fixed support and provided with a cranked portion124 extend A manually operable lever 125 is also fixed upon the shaft 123 and is provided with a pawl for coactipn with a segmental rack 127. the lever bcing adapted to be; swung in a manner to so rock the shaft 123 as to cause the cranked portion 124' thereof to ride upwardly beneath the con necting rods 120 and elevate the rods in the manner stated. Of course the rods may be returned to lowered or active position by a reverse adjustment of the lever 125 when it is again desired to resume operationof th charge compression pistons 8 1 and 851 in order that the piston llQtJlfi and rod 7 may be cooled and the head tiluhricated, the said head 0 is formedlminteriorly with lubricant chambers 128 anil129 separated by a partition wall 130 located bet-Ween the 1&831714:

front and rear ends of the said head, the head being formed exteriorly with a circumferentially extending lubricant channel 131 located substantially in the plane of the partition wall 130 and being provided at the front and rear of the, channel with piston rings-;,132. Ports 133 and 134 establish communication between the channel 131 and the lubricant chambers 128 and 129 respectively, and the. head 6 is formed with a concentrically located core 135 into which the end of the rod *4 is fitted, the wall of this core being threaded for a portion of its length as at 136 to receive the reduced threaded extremity 13'6" ol the said rod 7 and being provided inwardly of its threaded portion with circumferentially extending channels 138 and 139. Ports 140 and 141 are formed in the wall of the core 135 and establish communication respectively between the channel 138 and lubricant chamber 123 and the channel 139mm! lubricent chamber 129. The piston rod 7 is formed with longitudinally extending lubricent passages or ducts 142 and 143 which at the head end of the rod communicate re spectively with the channels 138 and 139 preferably at points opposite the respective ports 140 and 141. Flexible tubes M4 and 1% ere introduced into the opposite end of the rod 7 and ere placed respectively in communication with the pi ssages 14:2 and 143. in practice, oil from any suitable source of supply under pressure will be forced through one of the tubes as for example the tube 14% and, after fiowing through the passage 142, will pass by way of the channel 138 and port 140 into the lubricant chamber 128 in the piston head 6. Being under pressure the oil will then be caused to iiow from this chamber to the port 133 end into the channel 155i where it suitable quantity thereof will be taken upby the surfaces of the piston head and lining well of the cylinder 1, the greater volume however being delivered through the port 134 into the chamber 129 and from this chamber through the port 141 into the passage 143, the oil being conducted from the system through the tube 145.

By setting the eccentrics and cams upon the crank shaft 13, the operation of the intake and exhaust valves and the operation of the charge compression istons is so timed as to bring about a cyc e of operation as follows:

In a, preceding cycle ofoperution the we ton 6 has moved from the dotted line position shown in Figure 3 to the full line position and during this movement the intake valve 61 has idled in closed position due to the engagement of the respective roller 76 against the low portion of the respective cemZ'Z. However the exhaust valve 3? has been moved to openposi'tion by the-riding .et which moment the nose of the respective cam 51v will ride out of engagement with the respective roller and the valve 37 will be immediately closed. At the moment of closing however the scevcnging of the respective end of the cylinder has been.

completed so that there is no appreciable residue of the exhuust gases in this end of the cylinder. 'lhe valve 37 will then idle in closed position until the )iston 6 has been again driven to its dott line position in Figure 3 and starts on its return strokeilo its full line position. traveling from the dotted to the full line position, the charge compremion piston is elevated against the tension of there/spective spring 93 through the upward swinging movement of the teppet erm 106 end the coaction of the upper side of this arm with the tappet heed 102 upon the stemof the said piston 85. The upward movement of this piston serves to draw into the c linder 32 a charge of explosive mixture on ich is trapped by the check valve 98. its soon as the arm 106 disengages from the respective teppet heed 102, the spring 93 sets immezli ately to force the charge compression pivton 85 on its downward stroke and the charge will be compressed by the vpiston a, degree in ratio to the force exerted by the spring 93 in expanding and such force ins-y be varied or regulated through adjustment of the nuts 91 and 92-encl tie plate as previously explained. At the moment the exhaust valve 37 has practically reached its closed position and the encl of the cylinder has been completely scavenged, the nose of the respective cam 77 riding against the respective roller 7 6 will open the intake valve 61, the movement of this valve to open position and the inrush of the compressed charge through the port 62 of the valve and into the end of the explosion cylinder 1 taking piece during the final closing of the eshsusl valve 37 and continuing until the moment when the piston 6 hes reached the limit of its stroke in the direction of its toll line position. As the abrupt end 33 of the nose of the com 7? rides past the roller 761 the valve 61 will be instantly moved to closed position, and at this moment the charge is tired. The piston is therefore impelled, bv the explosion of the charge, from the full line position shown in Figure 3 toward the dotted line position and as it so moves, the valves 36 and 60 will lee-actuated in precisely the some timed relution as that shove recited in connection with the valves 37 and 61, the operation of the charge compression piston While the piston is til) Fill

86 being likewise in the some timedrelation as previously explained in connection with the-piston 85. It will be evident that the degree which the charge is compressed in the charge compression cylinders may be varied or regulated by adwsting the plates 90 against which the lower ends of the s rin 93 bear, and it is further evident that ould the working conditions be such that all of the compressed charge is not delivered from either compression cylinder, the remainder of the charge will remain under compression and will be reserved until the corresponding piston is again moved on its up-stroke to take in a fresh volume of ex losive mixture. By adjusting the ivot b0 ts 69 in the links 71, the throw 0 the rods 67 and consequently the throw of the valves 60 and 61 may be regulated so as to rovide for the admissionof a greater or esser volume of the explosive mixture to ads the engine for heavy or light duty wor Having thus described the invention what is claimed as new is: 1

1. In aninternal combustion engine of the precompression type, an explosion cylinder, and means for compressing a gaseous charge prior to delivery to the said cylinder comprisin a charge compression cylinder having ac arge intake, and a part in com munication with the explosion chamber a piston working in the charge com ression cylinder, means operable to positive y. actuate the piston on its intake stroke and completely release the piston at the end of said stroke, and tension means for actuating the piston on its compression stroke.

2. In an internal combustioncngine of the precompression type, an explosion cylinder, and means for compressing a gaseous charge prior to delivery to the said cylinder,

comprising a charge compression cylinder having a charge intake, and a port in communication with the explosion cylinder, a piston working in the charge compression cylinder, tension means continuously urging the piston in the direction of its compression stroke, and means operable to positively move the piston on its intake stroke and completely release the some for actuation by the first mentioned means at the end o' fsaid stroke.

3. In an internal combusion engine of the precompression type, an explosion cylinder. and means for compressing a gaseous charge prior to delivery to the said cylinder comprising a charge compression cylinder having acharge intake, and a port in com munication with the explosion cylinder, a

piston working in the charge compression cylinder and having a rod extending exteriorly thereof, a compression spring'ucting upon the rod to continuously urge the piston in tho-direction of its compression stroke, and means operating to more the piston on its intake stroke and instantly disengage, from and release the same lot actuation by the said spring at the end of said stroke.

4. In an internal combustion engine of the precompression type, an explosion cylinder, and means for compressing a, gaseous charge prior to delivery to the said cylinder comprising a charge compression cylinder having a charge intake and a port in com-' the precompression type, an explosion cylinder, and means for compressing a gaseous'charge prior to delivery to the said cylinder comprisin a charge com ression cylinder having a 0 large intake an a port in communication with the explosion cylinder, a piston Working in the charge comression cylinder and having a rod, extendmg exteriorly thereof, an abutment member adjustably mounted upon the rod, u complession spring acting against the abut ment member to urge the piston in the di rection of its compression stroke, and means operating to move the piston on its intake stroke and instantly disengage from and release the same for actuation The o ring at the end of said stroke.

6. In an internal combustion engine of the prccompressiorr type, an explosion cylinder, and means for com ressing a gee cons charge prior to delivery to the said C \'ll!1(l! comprising a. charge com session cylinder having a charge intake; "on 'a port l pression cylinder, tension means urging; the a piston in the direction of its compression stroke, the piston havin a stem extending cxteriorly of the cylin er, a tappet heed upon the stem, and a tappet member ope" ing in connection with the said tappoi' heed to successively exert force upon the st? to move the piston on its intake stroke and then disengage to permit actuation of the piston by the tension means on its compression stroke.

7. In an internal combustion engine of the precompression type, an explosion cy];, inder, and means for compressing a gaseous charge prior to delivery to the said cylinder comprising a charge compression cylinder having a charge intake and a port in communication with the explosion cylresent;

inder, e piston working in the char e co mpression cylinder, means urging t e said piston in the direction of its compression stroke, the piston having a stem extending exteriorly of the cylinder, e tappet head upon the stem, and means coacting with the tappct head to move the'piston on its intake stroke, said means comprising an oscillatory tappet arm including pivotally supported relatively separable members, and means yieldably resistmg separation of the members, the members, in the movement of the arm in one direction, being arranged to ride over and past the ta pet head and engage behind the same, on in the movement of the arm in the otherdirection being arranged to act against the head to exert force upon the said stem and finally disengage from the'hesd to release the piston for actuation by the said urging means. 8. In an internal combustion engine of the precompression type, an explosion cylinder, charge compression cylinders each in communication with a respective end of the ex plosion cylinder and each having a charge intake, a piston Working in each char compression cylinder, :1 piston operating 1n the explosion cylinder, :1 shaft driven from the said piston, means urging the charge compression pistons in the direction of their compression stroke, and means for actuatingthe charge compression pistons on their intake strokes comprising rock shafts, tappet arms carried by the shafts, stems extending from the pistons, tappet elements upon the stems engageable by the tappet iirms'whcn the arms are swung in one direc- I tion whereby to eiicot movement of the respective piston on its intake stroke and then disengage to permit actuation of the piston by the urging means, crank elements upon'the said rock shafts, and connecting rods having crank connection with the first mentioned shaft and separably engaged with the crank elements upon the rock shafts.

9. In an internal combustion engine of the the said piston, means or 'ing the charge Btu precompression type, an explosion cylinder, charge compression cylinders each in co munication with arespective end of the so explosion cylinder and each having a charge intake, a piston working in each cherge compression cylinder, a piston operating in the explosioncylinder, a shaft driven from compression pistons in the irection of their compression stroke, and means for cctueting the charge compression pistons on their intake strokes. comprising rock shafts, ts pet arms carried by the shafts, stems exten ing from the pistons, tappet elements upon the stems cngageable by the tappet arms when the arms are swung in one direction whereby to effect movement of the respective pistonv on its intake stroke and then disen go to permit actuation of the piston by t e urging means, crank elements upon the said rock shafts, connectin rods having crenl: connection with the rst inentioned shaft and separsbiy engaged with the crank eiements upon the rock shafts, end means operable to disengegejhe connecting rods from the said crank elements whereby to render the teppet arms inactive.

10. In an internal combustion engine of the precompression type, an explosion cyi inder, a head upon one end thereof having en exhaust port and an intake'port, siide valve controlling the exhaust port, a slide valve eontrolhn the intake port, means operating the said valves in timed relation,

a charge compression cylinder upon head in communication with the intake port, a piston Working in the said charge mm pression -cylinder, means for actuating the piston, an intake manifold upon the plosion cylinder in communication with charge compression cylinder, and a, she valve within the intake manifold in po 7 tion to be exposed upon removal of the inder heed.

In testimony whereof I affix my signature.

ROBERT S. WITTMEIER. [it s} 

